package day1125;
public class Demo2 {
    public static void main(String[] args) {
        double  rs=0;
        //1.先用do-while循环循环10次，打印这10个数
        int i=1;
        do{
            rs= rs +  Math.pow(10,i)-1 ;
            i++;
        }while(i<=10);
        System.out.println(rs);
    }
}
